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<a name="libgimp3-gimpdrawablecolor"></a><div class="titlepage"></div>
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<td valign="top">
<h2><span class="refentrytitle"><a name="libgimp3-gimpdrawablecolor.top_of_page"></a>gimpdrawablecolor</span></h2>
<p>gimpdrawablecolor — Functions for manipulating a drawable's color.</p>
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<td class="gallery_image" valign="top" align="right"></td>
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<div class="refsect1">
<a name="libgimp3-gimpdrawablecolor.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_proto_type">
<col class="functions_proto_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-brightness-contrast" title="gimp_drawable_brightness_contrast ()">gimp_drawable_brightness_contrast</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-color-balance" title="gimp_drawable_color_balance ()">gimp_drawable_color_balance</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-colorize-hsl" title="gimp_drawable_colorize_hsl ()">gimp_drawable_colorize_hsl</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-curves-explicit" title="gimp_drawable_curves_explicit ()">gimp_drawable_curves_explicit</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-curves-spline" title="gimp_drawable_curves_spline ()">gimp_drawable_curves_spline</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-desaturate" title="gimp_drawable_desaturate ()">gimp_drawable_desaturate</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-equalize" title="gimp_drawable_equalize ()">gimp_drawable_equalize</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-histogram" title="gimp_drawable_histogram ()">gimp_drawable_histogram</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-hue-saturation" title="gimp_drawable_hue_saturation ()">gimp_drawable_hue_saturation</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-invert" title="gimp_drawable_invert ()">gimp_drawable_invert</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-levels" title="gimp_drawable_levels ()">gimp_drawable_levels</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-levels-stretch" title="gimp_drawable_levels_stretch ()">gimp_drawable_levels_stretch</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-posterize" title="gimp_drawable_posterize ()">gimp_drawable_posterize</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">gboolean</span>
</td>
<td class="function_name">
<a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-threshold" title="gimp_drawable_threshold ()">gimp_drawable_threshold</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="libgimp3-gimpdrawablecolor.description"></a><h2>Description</h2>
<p>Functions for manipulating a drawable's color, including curves and
histograms.</p>
</div>
<div class="refsect1">
<a name="libgimp3-gimpdrawablecolor.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="gimp-drawable-brightness-contrast"></a><h3>gimp_drawable_brightness_contrast ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_brightness_contrast (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                                   <em class="parameter"><code><span class="type">gdouble</span> brightness</code></em>,
                                   <em class="parameter"><code><span class="type">gdouble</span> contrast</code></em>);</pre>
<p>Modify brightness/contrast in the specified drawable.</p>
<p>This procedures allows the brightness and contrast of the specified
drawable to be modified. Both 'brightness' and 'contrast' parameters
are defined between -0.5 and 0.5.</p>
<div class="refsect3">
<a name="gimp-drawable-brightness-contrast.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>brightness</p></td>
<td class="parameter_description"><p>Brightness adjustment.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>contrast</p></td>
<td class="parameter_description"><p>Contrast adjustment.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-brightness-contrast.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-color-balance"></a><h3>gimp_drawable_color_balance ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_color_balance (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                             <em class="parameter"><code><a href="../html/libgimpbase3-gimpbaseenums.html#GimpTransferMode"><span class="type">GimpTransferMode</span></a> transfer_mode</code></em>,
                             <em class="parameter"><code><span class="type">gboolean</span> preserve_lum</code></em>,
                             <em class="parameter"><code><span class="type">gdouble</span> cyan_red</code></em>,
                             <em class="parameter"><code><span class="type">gdouble</span> magenta_green</code></em>,
                             <em class="parameter"><code><span class="type">gdouble</span> yellow_blue</code></em>);</pre>
<p>Modify the color balance of the specified drawable.</p>
<p>Modify the color balance of the specified drawable. There are three
axis which can be modified: cyan-red, magenta-green, and
yellow-blue. Negative values increase the amount of the former,
positive values increase the amount of the latter. Color balance can
be controlled with the 'transfer_mode' setting, which allows
shadows, mid-tones, and highlights in an image to be affected
differently. The 'preserve-lum' parameter, if TRUE, ensures that the
luminosity of each pixel remains fixed.</p>
<div class="refsect3">
<a name="gimp-drawable-color-balance.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>transfer_mode</p></td>
<td class="parameter_description"><p>Transfer mode.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>preserve_lum</p></td>
<td class="parameter_description"><p>Preserve luminosity values at each pixel.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>cyan_red</p></td>
<td class="parameter_description"><p>Cyan-Red color balance.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>magenta_green</p></td>
<td class="parameter_description"><p>Magenta-Green color balance.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>yellow_blue</p></td>
<td class="parameter_description"><p>Yellow-Blue color balance.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-color-balance.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-colorize-hsl"></a><h3>gimp_drawable_colorize_hsl ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_colorize_hsl (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                            <em class="parameter"><code><span class="type">gdouble</span> hue</code></em>,
                            <em class="parameter"><code><span class="type">gdouble</span> saturation</code></em>,
                            <em class="parameter"><code><span class="type">gdouble</span> lightness</code></em>);</pre>
<p>Render the drawable as a grayscale image seen through a colored
glass.</p>
<p>Desaturates the drawable, then tints it with the specified color.
This tool is only valid on RGB color images. It will not operate on
grayscale drawables.</p>
<div class="refsect3">
<a name="gimp-drawable-colorize-hsl.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>hue</p></td>
<td class="parameter_description"><p>Hue in degrees.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>saturation</p></td>
<td class="parameter_description"><p>Saturation in percent.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>lightness</p></td>
<td class="parameter_description"><p>Lightness in percent.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-colorize-hsl.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-curves-explicit"></a><h3>gimp_drawable_curves_explicit ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_curves_explicit (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                               <em class="parameter"><code><a class="link" href="libgimp3-gimpenums.html#GimpHistogramChannel" title="enum GimpHistogramChannel"><span class="type">GimpHistogramChannel</span></a> channel</code></em>,
                               <em class="parameter"><code><span class="type">gint</span> num_values</code></em>,
                               <em class="parameter"><code>const <span class="type">gdouble</span> *values</code></em>);</pre>
<p>Modifies the intensity curve(s) for specified drawable.</p>
<p>Modifies the intensity mapping for one channel in the specified
drawable. The channel can be either an intensity component, or the
value. The 'values' parameter is an array of doubles which
explicitly defines how each pixel value in the drawable will be
modified. Use the <a href="/local/head/share/gtk-doc/html/libgimp/libgimp-gimpcolor.html#gimp-curves-spline"><code class="function">gimp_curves_spline()</code></a> function to modify intensity
levels with Catmull Rom splines.</p>
<div class="refsect3">
<a name="gimp-drawable-curves-explicit.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>The channel to modify.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>num_values</p></td>
<td class="parameter_description"><p>The number of values in the new curve.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>values</p></td>
<td class="parameter_description"><p>The explicit curve. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter points to an array of items."><span class="acronym">array</span></acronym> length=num_values][<acronym title="Generics and defining elements of containers and arrays."><span class="acronym">element-type</span></acronym> gdouble]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-curves-explicit.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-curves-spline"></a><h3>gimp_drawable_curves_spline ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_curves_spline (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                             <em class="parameter"><code><a class="link" href="libgimp3-gimpenums.html#GimpHistogramChannel" title="enum GimpHistogramChannel"><span class="type">GimpHistogramChannel</span></a> channel</code></em>,
                             <em class="parameter"><code><span class="type">gint</span> num_points</code></em>,
                             <em class="parameter"><code>const <span class="type">gdouble</span> *points</code></em>);</pre>
<p>Modifies the intensity curve(s) for specified drawable.</p>
<p>Modifies the intensity mapping for one channel in the specified
drawable. The channel can be either an intensity component, or the
value. The 'points' parameter is an array of doubles which define a
set of control points which describe a Catmull Rom spline which
yields the final intensity curve. Use the <a href="/local/head/share/gtk-doc/html/libgimp/libgimp-gimpcolor.html#gimp-curves-explicit"><code class="function">gimp_curves_explicit()</code></a>
function to explicitly modify intensity levels.</p>
<div class="refsect3">
<a name="gimp-drawable-curves-spline.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>The channel to modify.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>num_points</p></td>
<td class="parameter_description"><p>The number of values in the control point array.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>points</p></td>
<td class="parameter_description"><p>The spline control points: { cp1.x, cp1.y, cp2.x, cp2.y, ... }. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter points to an array of items."><span class="acronym">array</span></acronym> length=num_points][<acronym title="Generics and defining elements of containers and arrays."><span class="acronym">element-type</span></acronym> gdouble]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-curves-spline.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-desaturate"></a><h3>gimp_drawable_desaturate ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_desaturate (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                          <em class="parameter"><code><a href="../html/libgimpbase3-gimpbaseenums.html#GimpDesaturateMode"><span class="type">GimpDesaturateMode</span></a> desaturate_mode</code></em>);</pre>
<p>Desaturate the contents of the specified drawable, with the
specified formula.</p>
<p>This procedure desaturates the contents of the specified drawable,
with the specified formula. This procedure only works on drawables
of type RGB color.</p>
<div class="refsect3">
<a name="gimp-drawable-desaturate.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>desaturate_mode</p></td>
<td class="parameter_description"><p>The formula to use to desaturate.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-desaturate.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-equalize"></a><h3>gimp_drawable_equalize ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_equalize (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                        <em class="parameter"><code><span class="type">gboolean</span> mask_only</code></em>);</pre>
<p>Equalize the contents of the specified drawable.</p>
<p>This procedure equalizes the contents of the specified drawable.
Each intensity channel is equalized independently. The equalized
intensity is given as inten' = (255 - inten). The 'mask_only' option
specifies whether to adjust only the area of the image within the
selection bounds, or the entire image based on the histogram of the
selected area. If there is no selection, the entire image is
adjusted based on the histogram for the entire image.</p>
<div class="refsect3">
<a name="gimp-drawable-equalize.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>mask_only</p></td>
<td class="parameter_description"><p>Equalization option.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-equalize.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-histogram"></a><h3>gimp_drawable_histogram ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_histogram (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                         <em class="parameter"><code><a class="link" href="libgimp3-gimpenums.html#GimpHistogramChannel" title="enum GimpHistogramChannel"><span class="type">GimpHistogramChannel</span></a> channel</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> start_range</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> end_range</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> *mean</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> *std_dev</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> *median</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> *pixels</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> *count</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> *percentile</code></em>);</pre>
<p>Returns information on the intensity histogram for the specified
drawable.</p>
<p>This tool makes it possible to gather information about the
intensity histogram of a drawable. A channel to examine is first
specified. This can be either value, red, green, or blue, depending
on whether the drawable is of type color or grayscale. Second, a
range of intensities are specified. The <a class="link" href="libgimp3-gimpdrawablecolor.html#gimp-drawable-histogram" title="gimp_drawable_histogram ()"><code class="function">gimp_drawable_histogram()</code></a>
function returns statistics based on the pixels in the drawable that
fall under this range of values. Mean, standard deviation, median,
number of pixels, and percentile are all returned. Additionally, the
total count of pixels in the image is returned. Counts of pixels are
weighted by any associated alpha values and by the current selection
mask. That is, pixels that lie outside an active selection mask will
not be counted. Similarly, pixels with transparent alpha values will
not be counted. The returned mean, std_dev and median are in the
range (0..255) for 8-bit images or if the plug-in is not
precision-aware, and in the range (0.0..1.0) otherwise.</p>
<div class="refsect3">
<a name="gimp-drawable-histogram.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>The channel to query.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>start_range</p></td>
<td class="parameter_description"><p>Start of the intensity measurement range.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>end_range</p></td>
<td class="parameter_description"><p>End of the intensity measurement range.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>mean</p></td>
<td class="parameter_description"><p>Mean intensity value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>std_dev</p></td>
<td class="parameter_description"><p>Standard deviation of intensity values. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>median</p></td>
<td class="parameter_description"><p>Median intensity value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>pixels</p></td>
<td class="parameter_description"><p>Alpha-weighted pixel count for entire image. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>count</p></td>
<td class="parameter_description"><p>Alpha-weighted pixel count for range. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>percentile</p></td>
<td class="parameter_description"><p>Percentile that range falls under. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-histogram.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-hue-saturation"></a><h3>gimp_drawable_hue_saturation ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_hue_saturation (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                              <em class="parameter"><code><a href="../html/libgimpbase3-gimpbaseenums.html#GimpHueRange"><span class="type">GimpHueRange</span></a> hue_range</code></em>,
                              <em class="parameter"><code><span class="type">gdouble</span> hue_offset</code></em>,
                              <em class="parameter"><code><span class="type">gdouble</span> lightness</code></em>,
                              <em class="parameter"><code><span class="type">gdouble</span> saturation</code></em>,
                              <em class="parameter"><code><span class="type">gdouble</span> overlap</code></em>);</pre>
<p>Modify hue, lightness, and saturation in the specified drawable.</p>
<p>This procedure allows the hue, lightness, and saturation in the
specified drawable to be modified. The 'hue-range' parameter
provides the capability to limit range of affected hues. The
'overlap' parameter provides blending into neighboring hue channels
when rendering.</p>
<div class="refsect3">
<a name="gimp-drawable-hue-saturation.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>hue_range</p></td>
<td class="parameter_description"><p>Range of affected hues.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>hue_offset</p></td>
<td class="parameter_description"><p>Hue offset in degrees.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>lightness</p></td>
<td class="parameter_description"><p>Lightness modification.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>saturation</p></td>
<td class="parameter_description"><p>Saturation modification.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>overlap</p></td>
<td class="parameter_description"><p>Overlap other hue channels.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-hue-saturation.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-invert"></a><h3>gimp_drawable_invert ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_invert (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                      <em class="parameter"><code><span class="type">gboolean</span> linear</code></em>);</pre>
<p>Invert the contents of the specified drawable.</p>
<p>This procedure inverts the contents of the specified drawable. Each
intensity channel is inverted independently. The inverted intensity
is given as inten' = (255 - inten). If 'linear' is TRUE, the
drawable is inverted in linear space.</p>
<div class="refsect3">
<a name="gimp-drawable-invert.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>linear</p></td>
<td class="parameter_description"><p>Whether to invert in linear space.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-invert.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-levels"></a><h3>gimp_drawable_levels ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_levels (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                      <em class="parameter"><code><a class="link" href="libgimp3-gimpenums.html#GimpHistogramChannel" title="enum GimpHistogramChannel"><span class="type">GimpHistogramChannel</span></a> channel</code></em>,
                      <em class="parameter"><code><span class="type">gdouble</span> low_input</code></em>,
                      <em class="parameter"><code><span class="type">gdouble</span> high_input</code></em>,
                      <em class="parameter"><code><span class="type">gboolean</span> clamp_input</code></em>,
                      <em class="parameter"><code><span class="type">gdouble</span> gamma</code></em>,
                      <em class="parameter"><code><span class="type">gdouble</span> low_output</code></em>,
                      <em class="parameter"><code><span class="type">gdouble</span> high_output</code></em>,
                      <em class="parameter"><code><span class="type">gboolean</span> clamp_output</code></em>);</pre>
<p>Modifies intensity levels in the specified drawable.</p>
<p>This tool allows intensity levels in the specified drawable to be
remapped according to a set of parameters. The low/high input levels
specify an initial mapping from the source intensities. The gamma
value determines how intensities between the low and high input
intensities are interpolated. A gamma value of 1.0 results in a
linear interpolation. Higher gamma values result in more high-level
intensities. Lower gamma values result in more low-level
intensities. The low/high output levels constrain the final
intensity mapping--that is, no final intensity will be lower than
the low output level and no final intensity will be higher than the
high output level. This tool is only valid on RGB color and
grayscale images.</p>
<div class="refsect3">
<a name="gimp-drawable-levels.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>The channel to modify.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>low_input</p></td>
<td class="parameter_description"><p>Intensity of lowest input.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>high_input</p></td>
<td class="parameter_description"><p>Intensity of highest input.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>clamp_input</p></td>
<td class="parameter_description"><p>Clamp input values before applying output levels.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>gamma</p></td>
<td class="parameter_description"><p>Gamma adjustment factor.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>low_output</p></td>
<td class="parameter_description"><p>Intensity of lowest output.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>high_output</p></td>
<td class="parameter_description"><p>Intensity of highest output.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>clamp_output</p></td>
<td class="parameter_description"><p>Clamp final output values.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-levels.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-levels-stretch"></a><h3>gimp_drawable_levels_stretch ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_levels_stretch (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>);</pre>
<p>Automatically modifies intensity levels in the specified drawable.</p>
<p>This procedure allows intensity levels in the specified drawable to
be remapped according to a set of guessed parameters. It is
equivalent to clicking the \"Auto\" button in the Levels tool.</p>
<div class="refsect3">
<a name="gimp-drawable-levels-stretch.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-levels-stretch.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-posterize"></a><h3>gimp_drawable_posterize ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_posterize (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                         <em class="parameter"><code><span class="type">gint</span> levels</code></em>);</pre>
<p>Posterize the specified drawable.</p>
<p>This procedures reduces the number of shades allows in each
intensity channel to the specified 'levels' parameter.</p>
<div class="refsect3">
<a name="gimp-drawable-posterize.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>levels</p></td>
<td class="parameter_description"><p>Levels of posterization.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-posterize.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
<hr>
<div class="refsect2">
<a name="gimp-drawable-threshold"></a><h3>gimp_drawable_threshold ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>
gimp_drawable_threshold (<em class="parameter"><code><a class="link" href="GimpDrawable.html" title="gimpdrawable"><span class="type">GimpDrawable</span></a> *drawable</code></em>,
                         <em class="parameter"><code><a class="link" href="libgimp3-gimpenums.html#GimpHistogramChannel" title="enum GimpHistogramChannel"><span class="type">GimpHistogramChannel</span></a> channel</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> low_threshold</code></em>,
                         <em class="parameter"><code><span class="type">gdouble</span> high_threshold</code></em>);</pre>
<p>Threshold the specified drawable.</p>
<p>This procedures generates a threshold map of the specified drawable.
All pixels between the values of 'low_threshold' and
'high_threshold', on the scale of 'channel' are replaced with white,
and all other pixels with black.</p>
<div class="refsect3">
<a name="gimp-drawable-threshold.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>drawable</p></td>
<td class="parameter_description"><p>The drawable.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>channel</p></td>
<td class="parameter_description"><p>The channel to base the threshold on.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>low_threshold</p></td>
<td class="parameter_description"><p>The low threshold value.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>high_threshold</p></td>
<td class="parameter_description"><p>The high threshold value.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gimp-drawable-threshold.returns"></a><h4>Returns</h4>
<p> TRUE on success.</p>
</div>
<p class="since">Since: <a class="link" href="api-index-2-10.html#api-index-2.10">2.10</a></p>
</div>
</div>
</div>
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